Components

Components are the basic building blocks of circuits. An individual component can be thought of as a single physical device in a circuit. We used to think of them as the resistors, capacitors, diodes, and other discrete components that make up our electronics, but as technology has advanced more and more devices have been added to this category. Components can be categorized in a variety of ways. Sometimes this might be by their electrical characteristics, like resistors and capacitors, while other devices, like sensors, are categorized by their use. In some cases this can result in a component that is listed twice. For example, a temperature sensing resistor is both a resistor and a sensor.

Compound components known as modules have steadily increased in popularity, making it easier than ever to add specific functionality to a circuit, whether it be in the form of a power supply, wireless radio, or one of the many other types of modules. Microcontroller Boards are but one example. Integrated circuits are another form of compound components, and there are hundreds of kinds available for a wide range of applications.

Active Components

Lots of people put a microprocessor and most of the other essential stuff on a tiny little demo board, easy to plug into your solderless breadboard (or your custom PCB) that has just a few more things that make your project special.